Company Related Questions:
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Who is Dredging Supply Company, Inc.?
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What is a Piranha Class Dredge?
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What is a Moray Class Dredge?
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What is a Barracuda Class Dredge?
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What is a Shark Class Dredge?
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What is a Marlin Class Dredge?
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Why is Dredging Supply Company, Inc. my best choice as a dredge manufacturer?
Specific Dredge Questions:
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At what digging depth should I consider a ladder pump?
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What is meant by the term "critical line velocity"?
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Why does Dredging Supply Company, Inc. size the suction relief valve smaller than some of the other manufacturers of similar systems?
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For an electric dredge pump system, should I choose AC or DC?
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Why does Dredging Supply Company, Inc. use square flotation tanks instead of round tanks?
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Does Dredging Supply Company, Inc. allow me as a potential customer to contact and/or visit other customers that they have sold dredges to?
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Why does the Marlin dredge employ (in their ladder pump drive system) the torque tube instead of the line shaft with cutlass bearings?
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Why are Dredging Supply Company's dredges PLC controlled instead of being equipped with manual controls?
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When does a dredge pump require more horsepower? On a short line or on a long line?
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Why is it important to choose a dredge manufacturer that engineers, builds, and programs "in house" the electrical and electronic packages being used on their dredges?
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When we purchase a dredge from Dredging Supply Company, Inc., can we get operator training from you as a dredge manufacturer?
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In the future, if I need a larger or different dredge, will Dredging Supply Company, Inc. help sell or take on trade my dredge when I buy a new one from DSC?
1. Who is Dredging Supply Company, Inc.?
Dredging Supply Company, Inc. is a world-class dredge manufacturer, which provides this highly specialized industry with new, customized dredges, dredge parts, supplies, and our overall engineering experience. With over a decade of experience, DSC has developed a dominant role in the dredge manufacturing industry and we pride ourselves with being the "World's Leader in Portable Dredges". Whether you are looking for a new, used, or custom-built dredge, call DSC to help you with your dredging provisions.
2. What is a Piranha Class Dredge?
A highly portable true cutterhead dredge, which is conventional in design and is offered in both 8-inch and 10-inch discharge configurations. For more information, please consult DSC's Piranha page.
3. What is a Moray Class Dredge?
A swinging ladder dredge that also equipped with an underwater dredge pump. The newly designed Moray dredge has proven itself to be highly productive and transportable. For more information, please consult DSC's Moray page.
4. What is a Barracuda Class Dredge?
A swinging ladder dredge with standard discharge sizes ranging from 10-inch through 16-inch. The Barracuda dredges have been most commonly used in waterway maintenance and lake revitalization projects. For more information, please consult DSC's Barracuda page.
5. What is a Shark Class Dredge?
A conventional dredge-operating configuration with modular design for ease of transportation; most commonly used by sand & gravel producers and contractors. Standard discharge sizes range from 10-inch through 24-inch. For more information, please consult DSC's Shark page.
6. What is a Marlin Class Dredge?
Designed to meet the needs of deep mining deposits as an efficient tool to excavate materials. the Marlin can dredge depths exceeding 100 feet. This deep digging depth is made possible by the use of an underwater pump system with a high torque cutter drive assembly. For more information, please consult DSC's Marlin page.
7. Why is Dredging Supply Company, Inc. my best choice as a dredge manufacturer?
DSC is an experienced dredge manufacturer specializing in portable cutter suction, combination, environmental, maintenance, articulating ladder, sand and gravel dredges, and various other mining dredges, including underwater pump dredges. We want to customize a dredge for your particular needs; therefore, we are not afraid to think outside the box and try something different. We are also owned by a group of engineers that stay current on the latest trends and technology in the dredging industry and always know just what to recommend for your project.
1. At what digging depth should I consider a ladder pump?
The effect and benefit of a submerged pump is immediate even at shallow depths and low production rates; however, economic issues usually dictate this decision.
Without going to an elaborate jet system in the pump suction, which is very inefficient and costly at or near sea level if you plan to dig deeper than 45 feet and need to average more than 300 tons per hour of production, it is more cost effective to use a ladder pump or a combination ladder pump and hull mounted pump. At DSC any of our sales staff with the help of one of our four licensed professional engineers will gladly do a project analysis to help you choose the most cost effective dredge to satisfy your production needs.
2. What is meant by the term "critical line velocity"?
The lowest possible velocity at which the dredged material will stay in suspension and move through the pipeline in a heterogeneous mixture. Below this velocity the material begins to separate and fall out in the pipeline. There are no magic numbers that relate to all conditions and materials. This velocity changes with dredging conditions and the type of material being pumped. If the operator continues to pump below this point, the pipeline will plug with material and the dredge will be down. This is one more reason why DSC operator training is so important when purchasing a new dredge. DSC has developed automation systems such as flow control that helps in overcoming the challenges of line plugging.
3. Why does Dredging Supply Company, Inc. size the suction relief valve smaller than some of the other manufacturers of similar systems?
The answer to this question is twofold:
First, DSC sizes the suction relief valve large enough to allow the dredge pump to remain primed during a cave in situation, but small enough as to allow the negative pressure to remain high on the suction side of the pump, which will allow the material to continue to move through the suction mouthpiece and eventually clear the cave in material from the suction mouthpiece.
Secondly, if an excessive amount of water is added to the slurry mixture the density within the pump drops and can drop as low as a specific gravity of 1. The density of the material within the pump is now at a very low specific gravity and will not move the material in the discharge pipe, which is at a much greater density. When this happens, the operator must increase the speed of the pump substantially to prevent the line from immediately becoming plugged.
4. For an electric dredge pump system, should I choose AC or DC?
With economic considerations in mind, in the horsepower ranges of 600 to 1130 inclusive, DC would be the clear choice. This is primarily because of the remanufactured GE-752 traction motor. Below 600 horsepower, AC would be the economical choice. Above 1130 each case would have to be considered on an individual basis. Dredging Supply Company, Inc. will certainly explore all options based on power availability, customer preference, customer in-house electrical maintenance capabilities, and initial capital investment goals. DSC has extensive experience in DC, AC, and AC medium voltage drives and will help you, the customer, make the right choice every time. We owe no allegiance to any one electrical manufacture; therefore, we can choose from a wide array of manufacturers that best suit the customer’s overall needs.
5. Why does Dredging Supply Company, Inc. use square flotation tanks instead of round tanks?
Square tanks, although much more expensive to manufacture, are more stable for a given size than round tanks. Square tanks are also more user friendly because all you do is add handrails and you have a safe work platform. Special grating schemes have to be devised on round tanks to allow even a personnel walkway to be added to the top of the tank.
6. Does Dredging Supply Company, Inc. allow me as a potential customer to contact and/or visit other customers that they have sold dredges to?
We not only allow our potential customers to contact and visit with our established customers, but we highly recommend it. When making a capital investment as large as a dredge, we want to do everything in our power to help the potential customer achieve the comfort level they deserve.
7. Why does the Marlin dredge employ (in their ladder pump drive system) the torque tube instead of the line shaft with cutlass bearings?
The torque tubes, although more expensive, require less horsepower because of the use of antifriction bearings as opposed to the cutlass bearings that are basically rubber sleeve type bearings or “friction bearings”. Cutlass bearings have to be flushed with clean water, which not only requires horsepower to drive the water pump, but also is impossible to obtain in some dredging environments.
8. Why are Dredging Supply Company's dredges PLC controlled instead of being equipped with manual controls?
The PLC allows the dredge to interface with the processing plant, boosters, and allows different automation schemes to be employed. The PLC has also brought about a whole new dimension to the hydraulic control system. It has allowed the hydraulic oil, valves, and hose to stay in the hydraulic room or engine room and not to become part of the control room or lever room.
9. When does a dredge pump require more horsepower? On a short line or on a long line?
Required horsepower is dependent on pressure and flow rate. At a given flow rate, more horsepower is required on the long line than a short line. This is because a higher pressure is required to pump a longer pipeline at a given flow. At a given pump speed, more horsepower is required on a short line than a long line. This is because the lower friction on the short line induces a higher flow rate.
10. Why is it important to choose a dredge manufacturer that engineers, builds, and programs "in house" the electrical and electronic packages being used on their dredges?
One word, ACCOUNTABILTY. Unfortunately most dredge manufactures do not understand the electrical side and/or the dredge operational side of their business. That leads them to “sub out” these very important portions of the dredge engineering and manufacture. When this happens, the customer becomes dependent on this sub-contractor and can sometime be left holding the bag. At Dredging Supply Company, Inc. the dredge is designed by DSC engineers and wired by DSC electricians. If there is a problem, you as the customer has one call to make. The dredge manufacturer, no ifs, ands, or buts about it.
11. When we purchase a dredge from Dredging Supply Company, Inc., can we get operator training from you as a dredge manufacturer?
You not only get the training on your dredge when it is delivered and commissioned, but you also receive class room training as well as dredge simulator training. At this writing, DSC is the only manufacturer in the USA to offer this service.